Re: [PATCH 5.10] staging: gasket: interrupt: Clean interrupt_data after free

[Greg KH <gregkh@linuxfoundation.org>]

On Mon, May 15, 2023 at 03:29:50PM +0300, Esina Ekaterina wrote:
> Add interrupt_data = NULL after kfree(interrupt_data) in
> gasket_interrupt_init. It is needed to avoid double free
> in gasket_interrupt_cleanup, there is a check for NULL
> before kfree(interrupt_data).
> 
> Found by Astra Linux on behalf of Linux Verification Center
> (linuxtesting.org) with SVACE.
> 
> Fixes: 9a69f5087ccc ("drivers/staging: Gasket driver framework + Apex driver")
> Signed-off-by: Esina Ekaterina <eesina@astralinux.ru>
> ---
>  drivers/staging/gasket/gasket_interrupt.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/staging/gasket/gasket_interrupt.c b/drivers/staging/gasket/gasket_interrupt.c
> index 864342acfd86..48b664b9134a 100644
> --- a/drivers/staging/gasket/gasket_interrupt.c
> +++ b/drivers/staging/gasket/gasket_interrupt.c
> @@ -337,6 +337,7 @@ int gasket_interrupt_init(struct gasket_dev *gasket_dev)
>  			sizeof(*interrupt_data->eventfd_ctxs), GFP_KERNEL);
>  	if (!interrupt_data->eventfd_ctxs) {
>  		kfree(interrupt_data);
> +		interrupt_data = NULL;
>  		return -ENOMEM;
>  	}
>  
> @@ -346,6 +347,7 @@ int gasket_interrupt_init(struct gasket_dev *gasket_dev)
>  	if (!interrupt_data->interrupt_counts) {
>  		kfree(interrupt_data->eventfd_ctxs);
>  		kfree(interrupt_data);
> +		interrupt_data = NULL;
>  		return -ENOMEM;
>  	}
>  
> -- 
> 2.40.1
> 

<formletter>

This is not the correct way to submit patches for inclusion in the
stable kernel tree.  Please read:
    https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
for how to do this properly.

</formletter>